The present invention is related to a pallet system for containerizing packages of goods, particularly core wound strand material. More particularly, the present invention is related to the provision of molded pallets, separator sheets, and the use of shrink film as a container, all which improve the overall palletizing operation.
The transportation and storage of yarn packages is accomplished by stacking the individual yarn packages on pallets which themselves can be stacked on one another. A typical pallet system includes a base pallet disposed below the lowermost layer in a stack of yarn packages, a top pallet disposed above the uppermost layer in the stack, and one or more separator grids disposed between the layers in the stack. Side panels made of corrugated board are then applied to the pallets to stabilize the pallets and to form a container for transporting and storing the yarn packages. The pallets and separator grids typically include a series of projections called locator nodes which engage the winding tubes of the yarn packages to locate the yarn packages on the pallet and to prevent the lateral shifting of the yarn packages during handling and transportation of the loaded pallets. These pallet systems have served adequately for many years. However, there remain a number of areas in which such pallet systems need improvement.
Some types of pallet systems used in the past are designed to be reusable. The pallets are made from a tough, molded plastic and are intended to nest with one another to form a compact package for shipment back to the yarn supplier. Nestable pallets and separator sheets that both nest properly and reliably engage and support the yarn packages has been a problem. The corrugated side panels are not reusable and are usually discarded. This results in unnecessary waste and increases the cost of shipping since new corrugated panels must be purchased.
Another problem with prior art pallet systems is that misalignment of the yarn packages on the pallet is either different or may result in damage to the yarn packages. A pallet typically holds 9-16 packages of yarn in each layer. When placing the top pallet or a separator grid over the yarn packages in the layer beneath, it is necessary to align the locator nodes of the top pallet with the opening in the winding tubes of the yarn packages. This is a cumbersome and difficult task and sometimes a yarn package will be tilted off center. If the locator node does not engage the winding tube of a yarn package properly, then damage can be caused to the transfer tail or to the yarn adjacent the end of the winding tube. Damage to the winding tube could also occur which would adversely effect the pay-out of the yarn from the package.
Another problem with prior art pallet systems is that the pallets or separator grids are not designed to adequately handle stress loads, particular stress caused by acceleration loads. Damage to the pallets or separator grids sometimes occurs due to excessive loads. Such damage could render the pallets or separator grids unusable.